JP2003160853A - Method for carburizing narrow or deep hole - Google Patents
Method for carburizing narrow or deep holeInfo
- Publication number
- JP2003160853A JP2003160853A JP2001401751A JP2001401751A JP2003160853A JP 2003160853 A JP2003160853 A JP 2003160853A JP 2001401751 A JP2001401751 A JP 2001401751A JP 2001401751 A JP2001401751 A JP 2001401751A JP 2003160853 A JP2003160853 A JP 2003160853A
- Authority
- JP
- Japan
- Prior art keywords
- carburizing
- pipe
- heating chamber
- work
- unsaturated hydrocarbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005255 carburizing Methods 0.000 title claims abstract description 75
- 238000000034 method Methods 0.000 title claims abstract description 31
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 24
- 239000010959 steel Substances 0.000 claims abstract description 24
- 239000000463 material Substances 0.000 claims abstract description 12
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract 2
- 229930195733 hydrocarbon Natural products 0.000 claims abstract 2
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract 2
- 238000010438 heat treatment Methods 0.000 claims description 43
- 239000007789 gas Substances 0.000 claims description 33
- 229930195735 unsaturated hydrocarbon Natural products 0.000 claims description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- 230000001965 increasing effect Effects 0.000 claims description 6
- 239000002344 surface layer Substances 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 2
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 2
- 238000007789 sealing Methods 0.000 abstract description 2
- 235000019589 hardness Nutrition 0.000 description 13
- 239000010410 layer Substances 0.000 description 7
- 238000010791 quenching Methods 0.000 description 7
- 230000000171 quenching effect Effects 0.000 description 6
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003028 elevating effect Effects 0.000 description 2
- -1 ethylene, propylene, acetylene Chemical group 0.000 description 2
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- MWWATHDPGQKSAR-UHFFFAOYSA-N propyne Chemical group CC#C MWWATHDPGQKSAR-UHFFFAOYSA-N 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は、鋼材よりなる、パイプ
外面からパイプ内面に達する少なくとも１か所の貫通細
穴を具備したパイプ状ワークの、パイプ外面、及びパイ
プ内面、あるいは貫通細穴内面でさえ、浸炭処理による
均一な浸炭深さ、あるいは表面硬さを容易に得ることが
できる浸炭処理方法に関する。
【０００２】
【従来の技術】産業界では、鋼材よりなる少なくとも１
か所の貫通細穴を具備したパイプ状ワークの、外面ばか
りか、パイプ外面からパイプ内面に達する貫通細穴内
面、あるいはパイプ状ワーク内面への、浸炭処理による
均一な浸炭深さや表面硬さを得ることが要望されてい
る。
【０００３】従来、アセチレンやエチレンなどの不飽和
炭化水素ガスを浸炭ガスとして使用する真空浸炭処理に
おいて、ワーク表面の炭素濃度むらが少なく、ワーク表
面のセメンタイト析出を防止することができる浸炭処理
方法を提供することを目的として、図１に示す特開２０
００−３０３１６０号が提案されている。
【０００４】特開２０００−３０３１６０号に開示され
た浸炭処理方法は、加熱室１１内のワークを窒素雰囲気
中で所定の浸炭温度まで加熱したのち、加熱室１１内を
減圧した状態で、浸炭性ガスとしての鎖状不飽和炭化水
素ガスを断続的に供給し、加熱室１１内の圧力を比較的
短いサイクルで変動させながら浸炭させるものであっ
て、このとき使用する鎖状不飽和炭化水素ガスとして
は、エチレンやプロピレン、アセチレン、メチルアセチ
レンなどが用いられている。
【０００５】このような浸炭処理方法により、図３に示
す、鋼材よりなる貫通細穴２８を具備したパイプ状ワー
ク２３の浸炭処理を実施すると、真空の加熱室１１内に
大気圧の浸炭性ガスを供給することにより、加熱室１１
内と、鋼材よりなる貫通細穴２８を具備したパイプ状ワ
ーク２３の、パイプ部２５の気圧が同時に上昇し、加熱
室１１内と、鋼材よりなるパイプ状ワーク２３のパイプ
部２５の気圧差が発生しないため、浸炭性ガスがパイプ
状ワーク２３の内部にまで十分に浸透できない。そのた
め、図３、及び図４、図５に示すように、細穴内面２
４、あるいはパイプ部２５内面への、浸炭処理による均
一な浸炭深さ、あるいは均一な表面硬さを得ることがで
きないことを確認した。
【０００６】
【発明が解決しようとする課題】本発明に係る請求項１
は、鋼材よりなる、パイプ外面からパイプ内面に達する
少なくとも１か所の貫通細穴を具備したパイプ状ワーク
の外面、貫通細穴内面、あるいはパイプ状ワークのパイ
プ内面への浸炭処理による均一な浸炭深さ、均一な表面
硬さを容易に得ることができる、新規な方法を採用した
浸炭処理方法を提供することを課題とする。
【０００７】
【課題を解決するための手段】請求項１に係る浸炭処理
方法は、加熱室内において、窒素ガス中の大気圧で炉内
攪拌を利用し、鋼材ワークを浸炭温度まで加熱したの
ち、加熱室内を真空状態とすると共に、加熱室内の真空
状態を保持しながら、鎖状不飽和炭化水素ガスを加熱室
内へ断続的に直接添加し、鎖状不飽和炭化水素ガスを加
熱室内へ直接添加したことにより上昇した加熱室内の気
圧を、鎖状不飽和炭化水素ガスを加熱室内へ添加する以
前の加熱室内の気圧に減圧すると共に、鎖状不飽和炭化
水素ガスを加熱室外へ排気し、この、鎖状不飽和炭化水
素ガスの直接添加と、鎖状不飽和炭化水素ガスの添加後
の加熱室内の減圧、及び鎖状不飽和炭化水素ガスの加熱
室外への排気を繰り返すことにより、鋼製ワークの表面
層のみの炭素量を増加させる浸炭処理方法において、鋼
材よりなる、パイプ外面からパイプ内面に達する少なく
とも１か所の貫通細穴を具備したパイプ状ワークの、外
面のみならず、貫通細穴内面、あるいはパイプ状ワーク
のパイプ内面への浸炭処理時に、パイプ状ワークの両端
開放部を蓋などにより閉鎖することを特徴とするもので
ある。
【０００８】
【発明の実施の形態】本実施形態に係る浸炭処理方法
は、鋼材よりなるパイプ外面からパイプ内面に達する少
なくとも１か所の、例えば１〜６ｍｍの外径を有する貫
通細穴を具備したパイプ状ワークの、外面ばかりか、パ
イプ状ワークのパイプ内面、あるいは貫通細穴内面でさ
え、浸炭処理による均一な浸炭深さや表面硬さを得るこ
とができる浸炭処理方法である。なお、産業界において
も前述したように、鋼材よりなる貫通細穴を具備したパ
イプ状ワークの、貫通細穴内面でさえ、浸炭処理による
均一な浸炭深さや表面硬さを容易に得ることができる浸
炭処理方法が要望されている。以下、本発明の代表的な
実施形態を図面を参照して説明する。ただし、この実施
例に記載されている構成部品の寸法、形状、材質、その
相対位置などは、特に特定的な記載がないかぎりは、こ
の発明の範囲をそれらのみに限定する趣旨のものではな
く、単なる説明例にすぎない。
【０００９】特開２０００−３０３１６０号に開示され
た浸炭処理方法は、加熱室１１内のワークを窒素雰囲気
中で所定の浸炭温度まで加熱したのち、加熱室１１内を
減圧した状態で、浸炭性ガスとしての鎖状不飽和炭化水
素ガスを断続的に供給し、加熱室１１内の圧力を比較的
短いサイクルで変動させながら浸炭させるものであっ
て、このとき使用する鎖状不飽和炭化水素ガスとして
は、エチレンやプロピレン、アセチレン、メチルアセチ
レンなどが用いられている。
【００１０】図１に、特開２０００−３０３１６０号に
係わる浸炭処理方法による炉の構造の一例を示す。図１
に示す浸炭炉１２は、炉本体を形成する加熱室１１と、
焼入用の油槽１３を備えた前室１４から構成されてお
り、前室１４にはトレーに載置したワークを前室１４と
加熱室１１の間で移動させる炉内搬送装置１５と、浸炭
を終えたワークを油槽１３中の焼入油に浸漬するための
昇降装置１６を備えている。さらに、前室１４には、油
槽１３中の焼入油を加熱するためのチューブヒータ１７
と、焼入油を循環させるための攪拌ファン１８が設けて
あると共に、焼入油を冷却するための水冷装置（図示な
し）と、焼入油の温度を検出する熱伝対などを備えてい
る。
【００１１】一方、加熱室１１は、耐火物１９によって
内張された加熱室１１の内部に加熱源としてのラジアン
トチューブヒータ２０と、炉内温度を検出するための熱
伝対２１と、炉内の雰囲気を強制攪拌するためのファン
２２を備えており、炉内の温度むらをなくしてワークの
昇温を速やかなものとすることができるようになってい
る。さらに、加熱室１１および前室１４は、真空排気装
置（図示なし）を備え、それぞれ独立して気圧制御がで
きるようになっていると共に、ガス制御装置（図示な
し）を介して、窒素源、アセチレン源（共に図示なし）
に連結されている。
【００１２】このような構造を備えた浸炭炉１２を用い
た浸炭処理方法により、図２に示す、鋼材よりなる貫通
細穴２８を具備したパイプ状ワーク２３の浸炭処理を実
施するにあたり、本発明は、鋼材よりなる貫通細穴２８
を具備したパイプ状ワーク２３の、細穴内面２４などへ
の、均一な浸炭深さ、あるいは均一な浸炭硬さを得るた
めの浸炭処理時に、鋼材よりなる貫通細穴２８を具備し
たパイプ状ワーク２３の両端開放部２６をネジ棒２９に
より連結された２か所の蓋２７により閉鎖し密閉して浸
炭処理を実施することにある。このことにより、浸炭炉
１２の真空の加熱室１１内への、大気圧である浸炭性ガ
スの供給時においても、鋼材よりなる貫通細穴２８を具
備したパイプ状ワーク２３のパイプ部２５の気圧が、従
来のように同時に上昇することなく、加熱室１１内とパ
イプ状ワーク２３の内面との間に、気圧差を発生させる
ことができ、そのため、浸炭性ガスが貫通細穴２８を経
由し、加熱室１１と比較すると気圧の低い、密封された
パイプ部２５内面へと流入することにより、浸炭性ガス
をワークの細部にまで十分に供給し浸透させることがで
き、図２に示すように、鋼材よりなるパイプ状ワーク２
３の、細穴内面２４でさえ、均一な浸炭深さ、あるいは
均一な表面硬さを得ることができる。なお、図２に示
す、鋼材よりなるパイプ状ワーク２３の、細穴内面２４
への浸炭層が、均一な浸炭深さ、あるいは均一な表面硬
さであることは確認済みであり、従来の浸炭方法と比較
したその確認結果を、図４、及び図５に示す。図４、あ
るいは図５は、浸炭焼入が最も困難だと思われる、細穴
内面２４の表面硬さ、及び焼入深さを複数個測定した結
果である。これらの結果からも、細穴内面２４への均一
な浸炭深さ、あるいは均一な表面硬さが得られているこ
とは明らかである。その他本発明装置は、前にも述べた
ように上記しかつ図面に示した実施例に限定されるもの
ではなく、要旨を逸脱しない範囲内で適宜変更し得るも
のである。
【００１３】
【発明の効果】請求項１に係る、鋼材よりなる貫通細穴
を具備したパイプ状ワークの、外面をはじめ、貫通細穴
内面、あるいはパイプ状ワーク内面への、浸炭処理によ
る浸炭時に、パイプ状のワークの両端開放部を閉鎖して
おこなう、鎖状不飽和炭化水素ガスの直接添加と、鎖状
不飽和炭化水素ガスの添加後の加熱室内の減圧、及び鎖
状不飽和炭化水素ガスの加熱室外への排気を繰り返すこ
とにより、鋼製ワークの表面層のみの炭素量を増加させ
る浸炭処理方法によれば、従来、非常に困難であった、
鋼材よりなる貫通細穴を具備したパイプ状ワークの、貫
通細穴内面、あるいはパイプ状ワーク内面への、浸炭処
理を容易におこなうことができ、しかも、貫通細穴内面
でさえ、浸炭処理による均一な浸炭深さ、あるいは均一
な表面硬さを得ることができる、新規な浸炭処理方法を
提供することができる。また、上記の効果の他、エネル
ギーコストの低減、浸炭時間の短縮、などの効果が考え
られ、全体的に稼働費用の低減にも寄与できるものであ
る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer surface of a pipe-shaped workpiece made of steel and having at least one through-hole extending from the outer surface of the pipe to the inner surface of the pipe. The present invention relates to a carburizing method capable of easily obtaining a uniform carburizing depth or a surface hardness by carburizing even on the inner surface of a pipe or the inner surface of a through-hole. [0002] In the industry, at least one steel material is used.
The uniformity of carburizing depth and surface hardness of the pipe-shaped work with the through-holes at the locations, not only on the outer surface, but also on the inner surface of the through-holes reaching from the outer surface of the pipe to the inner surface of the pipe, or to the inner surface of the pipe-like work, by carburizing It is desired to obtain. Conventionally, in a vacuum carburizing treatment using an unsaturated hydrocarbon gas such as acetylene or ethylene as a carburizing gas, a carburizing treatment method capable of preventing uneven carbon concentration on the work surface and preventing the precipitation of cementite on the work surface. For the purpose of providing, FIG.
No. 00-303160 has been proposed. In the carburizing method disclosed in Japanese Patent Application Laid-Open No. 2000-303160, a work in a heating chamber 11 is heated to a predetermined carburizing temperature in a nitrogen atmosphere, and then the pressure in the heating chamber 11 is reduced. A chain unsaturated hydrocarbon gas is intermittently supplied as a gas and carburized while the pressure in the heating chamber 11 is changed in a relatively short cycle, and the chain unsaturated hydrocarbon gas used at this time is used. For example, ethylene, propylene, acetylene, methylacetylene and the like are used. [0005] When the carburizing treatment of the pipe-like work 23 having the through holes 28 made of steel as shown in FIG. 3 is carried out by such a carburizing method, the carburizing gas at atmospheric pressure is introduced into the vacuum heating chamber 11. To supply the heating chamber 11
At the same time, the air pressure of the pipe portion 25 of the pipe-shaped work 23 having the through-hole 28 made of steel material rises, and the pressure difference between the heating chamber 11 and the pipe portion 25 of the pipe-shaped work 23 made of steel material is increased. Since it is not generated, the carburizing gas cannot sufficiently penetrate into the inside of the pipe-shaped work 23. Therefore, as shown in FIG. 3, FIG. 4, and FIG.
No. 4, or it was confirmed that a uniform carburizing depth or a uniform surface hardness could not be obtained on the inner surface of the pipe portion 25 by carburizing. [0006] The first aspect of the present invention.
Is uniform carburization of the outer surface of a pipe-like work having at least one through-hole extending from the outer surface of the pipe to the inner surface of the pipe, the inner surface of the through-hole, or the inner surface of the pipe of the pipe-like work made of steel material. An object of the present invention is to provide a carburizing method using a novel method, which can easily obtain a depth and a uniform surface hardness. According to a first aspect of the present invention, there is provided a carburizing method, wherein a steel workpiece is heated to a carburizing temperature in a heating chamber by using a furnace agitator at atmospheric pressure in nitrogen gas. While maintaining the vacuum state in the heating chamber and maintaining the vacuum state in the heating chamber, chain-like unsaturated hydrocarbon gas is intermittently directly added into the heating chamber, and chain-like unsaturated hydrocarbon gas is directly added into the heating chamber. The pressure in the heating chamber increased by the pressure reduction was reduced to the pressure in the heating chamber before adding the chain unsaturated hydrocarbon gas into the heating chamber, and the chain unsaturated hydrocarbon gas was exhausted outside the heating chamber. By repeating the direct addition of the chain unsaturated hydrocarbon gas, the pressure reduction in the heating chamber after the addition of the chain unsaturated hydrocarbon gas, and the exhaust of the chain unsaturated hydrocarbon gas to the outside of the heating chamber, Work surface layer only In the carburizing treatment method for increasing the carbon content of a pipe-shaped work made of steel material and having at least one through-hole extending from the outer surface of the pipe to the inner surface of the pipe, not only the outer surface but also the inner surface of the through-hole or the pipe During the carburizing process on the inner surface of the pipe, the opening at both ends of the pipe-shaped work is closed by a lid or the like. [0008] The carburizing method according to the present embodiment comprises at least one through hole having an outer diameter of, for example, 1 to 6 mm from the outer surface of a steel pipe to the inner surface of the pipe. This is a carburizing method capable of obtaining a uniform carburized depth and surface hardness by carburizing not only on the outer surface of the formed pipe-shaped work, but also on the inner surface of the pipe of the pipe-shaped work or the inner surface of the through-hole. As described above in the industry, even in the inner surface of a through hole of a pipe-shaped work having a through hole made of steel, a uniform carburizing depth and surface hardness can be easily obtained by carburizing. There is a need for a carburizing method. Hereinafter, typical embodiments of the present invention will be described with reference to the drawings. However, the dimensions, shapes, materials, relative positions and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to them unless otherwise specified. , Are merely illustrative examples. In the carburizing method disclosed in Japanese Patent Application Laid-Open No. 2000-303160, after the work in the heating chamber 11 is heated to a predetermined carburizing temperature in a nitrogen atmosphere, the carburizing A chain unsaturated hydrocarbon gas is intermittently supplied as a gas and carburized while the pressure in the heating chamber 11 is changed in a relatively short cycle, and the chain unsaturated hydrocarbon gas used at this time is used. For example, ethylene, propylene, acetylene, methylacetylene and the like are used. FIG. 1 shows an example of a furnace structure by a carburizing method according to Japanese Patent Application Laid-Open No. 2000-303160. FIG.
The carburizing furnace 12 shown in FIG. 1 includes a heating chamber 11 forming a furnace body,
It is composed of a front chamber 14 having an oil tank 13 for quenching. In the front chamber 14, an in-furnace transfer device 15 for moving a work placed on a tray between the front chamber 14 and the heating chamber 11, An elevating device 16 is provided for immersing the finished workpiece in the quenching oil in the oil tank 13. Further, a tube heater 17 for heating the quenched oil in the oil tank 13 is provided in the front chamber 14.
And a stirring fan 18 for circulating the quenching oil, a water cooling device (not shown) for cooling the quenching oil, and a thermocouple for detecting the temperature of the quenching oil. I have. On the other hand, the heating chamber 11 includes a radiant tube heater 20 as a heating source inside the heating chamber 11 lined with a refractory 19, a thermocouple 21 for detecting a furnace temperature, and a A fan 22 for forcibly agitating the atmosphere is provided, so that the temperature in the furnace can be raised quickly without uneven temperature in the furnace. Further, the heating chamber 11 and the front chamber 14 are provided with a vacuum exhaust device (not shown) so that the pressure can be controlled independently of each other. Acetylene source (both not shown)
It is connected to. In carrying out the carburizing treatment of the pipe-like work 23 having the through holes 28 made of steel material by the carburizing treatment method using the carburizing furnace 12 having such a structure, the present invention is applied. Is a through-hole 28 made of steel.
The pipe-like work having a through-hole 28 made of steel material at the time of carburizing to obtain a uniform carburized depth or a uniform carburized hardness on the inner surface 24 of the small hole of the pipe-shaped work 23 provided with 23 is to carry out the carburizing process by closing and sealing the open portions 26 at both ends with two lids 27 connected by screw rods 29. Thus, even when the carburizing gas at the atmospheric pressure is supplied into the vacuum heating chamber 11 of the carburizing furnace 12, the pressure of the pipe portion 25 of the pipe-shaped work 23 having the through-hole 28 made of steel material is reduced. However, a pressure difference can be generated between the inside of the heating chamber 11 and the inner surface of the pipe-shaped work 23 without simultaneously rising as in the related art, so that the carburizing gas passes through the through-hole 28. By flowing into the inside of the sealed pipe portion 25, which has a lower atmospheric pressure than the heating chamber 11, the carburizing gas can be sufficiently supplied and penetrated into the details of the work, as shown in FIG. , Pipe-shaped work 2 made of steel
Third, even the inner surface 24 of the small hole can obtain a uniform carburized depth or a uniform surface hardness. In addition, as shown in FIG.
It has been confirmed that the carburized layer has a uniform carburized depth or a uniform surface hardness, and the results of the comparison with the conventional carburizing method are shown in FIGS. 4 and 5. FIG. 4 or FIG. 5 shows the results of measuring a plurality of surface hardnesses and quenching depths of the inner surface 24 of the fine hole, which are considered to be most difficult to carburize and quench. From these results, it is apparent that a uniform carburized depth or a uniform surface hardness on the inner surface 24 of the small hole is obtained. In addition, as described above, the present invention is not limited to the embodiment described above and shown in the drawings, but can be appropriately modified without departing from the gist. According to the first aspect of the present invention, when carburizing a pipe-shaped work having a through-hole made of steel material into the outer surface, the inner surface of the through-hole, or the inner surface of the pipe-shaped work by carburizing treatment. Direct addition of chain-like unsaturated hydrocarbon gas by closing both open ends of pipe-shaped work, decompression in heating chamber after addition of chain-like unsaturated hydrocarbon gas, and chain-like unsaturated hydrocarbon Conventionally, according to the carburizing method of increasing the amount of carbon only in the surface layer of the steel work by repeatedly exhausting the gas to the outside of the heating chamber, it has been extremely difficult.
Carburizing treatment can be easily performed on the inner surface of the through hole or the inner surface of the pipe-like work having the through hole made of steel, and even the inner surface of the through hole can be uniformly carburized. It is possible to provide a novel carburizing method capable of obtaining a high carburizing depth or a uniform surface hardness. Further, in addition to the above-described effects, effects such as a reduction in energy costs and a reduction in carburizing time are considered, which can contribute to a reduction in operating costs as a whole.
【図面の簡単な説明】
【図１】特開２０００−３０３１６０号に係る浸炭炉の
説明図である。
【図２】本発明の浸炭方法による浸炭後のワークの浸炭
層を示す説明図である。
【図３】従来の浸炭方法による浸炭後のワークの浸炭層
を示す説明図である。
【図４】本発明の浸炭方法による浸炭後のワークの浸炭
層と、従来の浸炭方法による浸炭後のワークの浸炭層
の、細穴内面表面硬さのバラツキを比較した図。
【図５】本発明の浸炭方法による浸炭後のワークの浸炭
層と、従来の浸炭方法による浸炭後のワークの浸炭層
の、細穴内面浸炭深さのバラツキを比較した図。
【符号の説明】
１１・・・加熱室 １２・・・浸炭炉
１３・・・油槽 １４・・・前室
１５・・・炉内搬送装置 １６・・・昇降装
置
１７・・・チューブヒータ １８・・・攪拌フ
ァン
１９・・・耐火物 ２０・・・ラジア
ントチューブヒータ
２１・・・熱伝対 ２２・・・ファン
２３・・・パイプ状ワーク ２４・・・細穴内
面
２５・・・パイプ部 ２６・・・両端開
放部
２７・・・蓋 ２８・・・貫通細
穴
２９・・・ネジ棒BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a carburizing furnace according to JP-A-2000-303160. FIG. 2 is an explanatory view showing a carburized layer of a work after carburizing by the carburizing method of the present invention. FIG. 3 is an explanatory view showing a carburized layer of a work after carburizing by a conventional carburizing method. FIG. 4 is a graph comparing the carburized layer of the work after carburizing by the carburizing method of the present invention and the carburized layer of the work after carburizing by the conventional carburizing method to the variation in the inner surface hardness of the fine holes. FIG. 5 is a graph comparing the carburized layer of the work after carburizing by the carburizing method of the present invention and the carburized layer of the work after carburizing by the conventional carburizing method, with a variation in the carburized depth of the inner surface of the fine hole. [Description of Signs] 11 ... heating chamber 12 ... carburizing furnace 13 ... oil tank 14 ... front chamber 15 ... in-furnace transfer device 16 ... elevating device 17 ... tube heater 18 Agitating fan 19 refractory 20 radiant tube heater 21 thermocouple 22 fan 23 pipe-like work 24 inner surface of small hole 25 pipe 26 ... Open ends 27 ... Lid 28 ... Through hole 29 ... Screw rod
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4K028 AA01 AB01 AC01 AC08 4K042 AA06 BA03 DA06 ────────────────────────────────────────────────── ─── Continuation of front page F term (reference) 4K028 AA01 AB01 AC01 AC08 4K042 AA06 BA03 DA06
Claims (1)
炭素を侵入させ、鋼製ワークの表面層のみの炭素量を増
加させるため、前記ワークを浸炭性ガス中において適当
な温度で適当な時間加熱した後冷却するガス浸炭処理方
法であって、 加熱室内において、窒素ガス中の大気圧で炉内攪拌を利
用し、鋼製ワークを浸炭温度まで加熱したのち、加熱室
内を真空状態とすると共に、加熱室内の真空状態を保持
しながら、鎖状不飽和炭化水素ガスを加熱室内へ断続的
に直接添加し、 鎖状不飽和炭化水素ガスを加熱室内へ直接添加したこと
により上昇した加熱室内の気圧を、鎖状不飽和炭化水素
ガスを加熱室内へ添加する以前の加熱室内の気圧に減圧
すると共に、鎖状不飽和炭化水素ガスを加熱室外へ排気
し、 この、鎖状不飽和炭化水素ガスの直接添加と、鎖状不飽
和炭化水素ガスの添加後の加熱室内の減圧、及び鎖状不
飽和炭化水素ガスの加熱室外への排気を繰り返すことに
より、鋼製ワークの表面層のみの炭素量を増加させる浸
炭処理方法において、 鋼材よりなる、パイプ外面からパイプ内面に達する少な
くとも１か所の貫通細穴を具備したパイプ状ワークの、
前記外面のみならず、パイプ状ワークのパイプ内面、あ
るいは前記貫通細穴内面をも、前記浸炭処理方法により
浸炭処理を実施するにあたり、パイプ状ワークのパイプ
部両端開放部を閉鎖することを特徴とする浸炭処理方
法。Claims 1. In order to infiltrate carbon into the surface of a steel work by a carburizing gas and increase the amount of carbon only in the surface layer of the steel work, the work is immersed in a carburizing gas. This is a gas carburizing treatment method in which heating is performed at an appropriate temperature for an appropriate time and then cooling, and in a heating chamber, the steel work is heated to the carburizing temperature by using a furnace agitator at atmospheric pressure in nitrogen gas, and then heated. While maintaining the vacuum state in the chamber and maintaining the vacuum state in the heating chamber, the chain unsaturated hydrocarbon gas was directly intermittently added directly into the heating chamber, and the chain unsaturated hydrocarbon gas was directly added into the heating chamber. The pressure inside the heating chamber, which has been increased by this, is reduced to the pressure inside the heating chamber before adding the chain unsaturated hydrocarbon gas into the heating chamber, and the chain unsaturated hydrocarbon gas is exhausted outside the heating chamber. Chain unsaturated By repeating the direct addition of hydrocarbon gas, the pressure reduction in the heating chamber after the addition of the chain unsaturated hydrocarbon gas, and the evacuation of the chain unsaturated hydrocarbon gas out of the heating chamber, only the surface layer of the steel work A carburizing method for increasing the carbon content of a pipe-like workpiece having at least one through-hole formed from a steel material and extending from an outer surface of the pipe to an inner surface of the pipe;
Not only the outer surface, but also the inner surface of the pipe of the pipe-shaped work, or the inner surface of the through-hole, when performing the carburizing treatment by the carburizing method, closing both open ends of the pipe portion of the pipe-shaped work. Carburizing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001401751A JP3721536B2 (en) | 2001-11-22 | 2001-11-22 | Carburizing method for narrow and deep holes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001401751A JP3721536B2 (en) | 2001-11-22 | 2001-11-22 | Carburizing method for narrow and deep holes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003160853A true JP2003160853A (en) | 2003-06-06 |
| JP3721536B2 JP3721536B2 (en) | 2005-11-30 |
Family
ID=19189847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001401751A Expired - Fee Related JP3721536B2 (en) | 2001-11-22 | 2001-11-22 | Carburizing method for narrow and deep holes |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3721536B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106119511A (en) * | 2016-08-31 | 2016-11-16 | 马鞍山市恒泰重工机械有限公司 | 9Cr2Mo smoothing roll heat treatment method based on aerofluxus quenching technical |
| CN106119510A (en) * | 2016-08-31 | 2016-11-16 | 马鞍山市恒泰重工机械有限公司 | A kind of smoothing roll quenching process |
| CN106282496A (en) * | 2016-08-31 | 2017-01-04 | 马鞍山市恒泰重工机械有限公司 | A kind of Heavy Straightening Roller processing method |
| CN114350902A (en) * | 2021-12-23 | 2022-04-15 | 中国航发哈尔滨东安发动机有限公司 | Process method for improving hardness consistency of infiltrated layer of medium-small-sized thin-wall bushing |
-
2001
- 2001-11-22 JP JP2001401751A patent/JP3721536B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106119511A (en) * | 2016-08-31 | 2016-11-16 | 马鞍山市恒泰重工机械有限公司 | 9Cr2Mo smoothing roll heat treatment method based on aerofluxus quenching technical |
| CN106119510A (en) * | 2016-08-31 | 2016-11-16 | 马鞍山市恒泰重工机械有限公司 | A kind of smoothing roll quenching process |
| CN106282496A (en) * | 2016-08-31 | 2017-01-04 | 马鞍山市恒泰重工机械有限公司 | A kind of Heavy Straightening Roller processing method |
| CN106119511B (en) * | 2016-08-31 | 2017-10-13 | 马鞍山市恒泰重工机械有限公司 | 9Cr2Mo smoothing roll heat treatment methods based on exhaust quenching technical |
| CN106282496B (en) * | 2016-08-31 | 2017-10-17 | 马鞍山市恒泰重工机械有限公司 | A kind of Heavy Straightening Roller processing method |
| CN114350902A (en) * | 2021-12-23 | 2022-04-15 | 中国航发哈尔滨东安发动机有限公司 | Process method for improving hardness consistency of infiltrated layer of medium-small-sized thin-wall bushing |
| CN114350902B (en) * | 2021-12-23 | 2023-11-07 | 中国航发哈尔滨东安发动机有限公司 | Technological method for improving medium-small size thin-wall bushing seepage layer hardness consistency |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3721536B2 (en) | 2005-11-30 |
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